1. Field of the Invention
The present invention relates to an image forming apparatus for forming an image by printing which corresponds to a sheet feeding direction, and more particularly, to an image forming apparatus which is capable of forming images on both sides of a sheet.
2. Description of Related Art
In recent years, a printing controller for use in a printer is arranged to perform printing operation by selecting various rotational angels of 0.degree. , 90.degree., 180.degree., 270.degree. of font data so that printing can be performed for any direction on a sheet transported in a fixed direction. Moreover, by combining sequential control of printing output, an image can be formed in any print layout on the sheet. Accordingly, it can freely comply with such requirement as performing printing on both sides of a sheet, or forming an image in any print layout, or forming an image which is bound in various methods. Further, the sheet feed direction can be freely selected either for lateral or longitudinal direction.
However, depending on the direction or placement of images to be printed on both sides of a sheet and depending on the method how the sheets are bound, printing has to be performed from the reverse direction corresponding with the sheet feed direction which is selected, and printing data has to be output in reverse order. In order to perform said operation, more complicated printing mechanism and control system have to be arranged, and eventually it requires expensive manufacturing cost.